Dentsu has purchased Aegis Group in a deal which Ad Age is reporting is worth $4.9 billion.

In Canada, this means Dentsu will be taking ownership of Aegis Group agencies Carat, Vizeum Canada, iProspect and Isobar.

Aegis CEO Jerry Buhlmann called the deal “transformational” in the Ad Age piece, and Tadashi Ishii, Dentsu’s president and CEO, said he and Jerry have “ambitions for a truly client-focused global communication network built in the digital age, and are looking forward to further innovating our business and continuing to contribute to our clients’ success.”

Dentsu has 21,600 employees in 29 countries and Aegis Group has 12,000, Buhlmann says the executive structure at Aegis will not be affected by the acquisition, with the current toppers in place until the end of 2013.

Photo: Buddawiggi, Flickr Creative Commons